1. Field of the Invention
The present invention relates generally to a geothermal heating and/or cooling system and more particularly to one having a first pipe and a second pipe which are integrally connected together and, in a preferred embodiment, one piece by an extruded process.
2. Description of the Related Art
In the field of geothermal heating and/or cooling systems, pipes are connected to the inlet and outlet of a heat exchanger and the pipes are placed underground so as to be able to gather heat from the ground in the winter time so as to be able to heat a house or other structure; and, to remove heat from such building and put it into the ground in the summer time when the house or other structure needs to be cool. Geothermal energy systems are well known, for example, U.S. Pat. No. 6,585,036 to Amerman et al shows a geothermal systems wherein heat transfer pipes are vertically disposed in wells.
Other geothermal heating and/or cooling systems can work very similar to the one shown in U.S. Pat. No. 6,585,036 to Amerman et al but the pipes are disposed in the ground horizontally, well below the surface of the ground, typically at 15 feet or so beneath the surface of the ground. In practice, for each hole that is bored, there is a pair of pipes that are placed into the hole in the ground. One of these pipes in each hole is for receiving heat exchanger fluid from the heat exchanger and the other pipe is for returning the fluid back to the heat exchanger. In order for this system to work efficiently, the pipes need to be separated to prevent the heat from the warmer pipe to be transferred directly across the hole to the pipe with the cooler part of the heat exchanger fluid. In other words, the heat needs to be exchanged with the ground or soil around the hole and not be exchanged with the other parallel pipe in the hole.
It has been determined that a major problem with installation of these pipes in the holes in the ground is that they are not always separated to the extent desired. When this occurs, for example, if both pipes touch one another, then the heat exchange will occur from the fluid in the hotter pipe to the fluid in the cooler pipe and the efficiency of the system will be lowered. In order to overcome this problem, grout has been introduced into the hole for the purpose of trying to separate the pipes and to insulate the pipes from one another in each hole. This solution is not been entirely acceptable because it is not a positive way to separate the pipes from one another.
One solution for keeping the pipes in each hole separated is a spacer or clip, for example as shown in U.S. Pat. No. 6,000,459 to Jeppesen. These clips are used in addition to introducing grout, such as bentonite, to keep the pipes separated and to help prevent heat exchange between the pipes directly from one to the other in the hole in the ground.
Consequently, it will be appreciated that there is a need for an apparatus to permanently and dependably position the geothermal heat exchanger pipes at a predetermined distance apart in a hole of a geothermal heating and/or cooling apparatus wherein the spacer is integral with the pipes.